If it were me, I'd do it for free because I would feel both guilty to mess it up for a client but also I know a happy client will come back in the future and refer me to others.

Even if I were sued, I document everything and obey the law, so I won't be found guilty.

I was guilty of the going against the Thomas Jefferson quote. 

I always felt guilty about my lack of tracking.

To that end, the IDFPR has authority to initiatedisciplinary proceedings against licensees for violations of the Illinois Real Estate Act of 2000.The IDFPR may “refuse to issue or renew a license, may place on probation, suspend, or revokeany license, reprimand, or take any other disciplinary or non-disciplinary action as theDepartment may deem proper or impose a fine not to exceed $25,000 upon any licensee underthis Act . . . for any one or combination of” the grounds for discipline set forth in §20-20 of theAct, 225 ILCS 454/20-20.Additionally, a licensee may be subject to both civil penalties and criminal liability for theunlicensed practice of real estate brokerage:Any person who practices, offers to practice, attempts to practice, or holds oneselfout to practice as a real estate broker, real estate salesperson, or leasing agentwithout being licensed under this Act shall, in addition to any other penaltyprovided by law, pay a civil penalty to the Department in an amount not to exceed$25,000 for each offense as determined by the Department. 225 ILCS 454/20-10(a).Any person who is found working or acting as a managing broker, real estatebroker, real estate salesperson, or leasing agent or holding himself or herself out asa licensed sponsoring broker, managing broker, real estate broker, real estatesalesperson, or leasing agent without being issued a valid existing license is guilty ofa Class A misdemeanor and on conviction of a second or subsequent offense theviolator shall be guilty of a Class 4 felony. 225 ILCS 454/20-22.It is a fundamental principle under Illinois law that parties can agree to any terms, and can contract in any situation, as long as there is no legal prohibition or public policy that dictates otherwise.Contracts for the sale of lands, tenements, or hereditaments or any interest in or concerning them for a term longer than one year must be in writing to satisfy the Frauds Act.

So, in my opinion it would be the safest bet would be to contact the real estate commission and ask, beg, plead with them to see it your way.

Wherever the word “operate” or “operating” as a broker, broker associate, or sales associate appears in this chapter; in any order, rule, or regulation of the commission; in any pleading, indictment, or information under this chapter; in any court action or proceeding; or in any order or judgment of a court, it shall be deemed to mean the commission of one or more acts described in this chapter as constituting or defining a broker, broker associate, or sales associate, not including, however, any of the exceptions stated therein.

I feel guilty not paying for 1/2". 

You won't unless sued and/or prosecuted by the state.If I buy a client's property, mark it up and then resell, I'm guilty of an illegal "net listing". 

Bottom Line (and I am guilty of this as well) - It's easy to let our limiting beliefs hold us back especially when real estate has become "sexy" again and there are signs of it (no pun intended) all around us.